Manipulating Spectra

After a spectrum is loaded into profit, a thumbnail of the entire spectrum is placed in the Thumbnail Window (using the default units, wavelength or energy, as selected in the File$\rightarrow$Preferences menu item), and it is also put into the Main Plot Window. At any time, the Main Plot Window can be reset to the plot shown in the Thumbnail Window by double-clicking on the Thumbnail plot.

Profit's most fundamental ability is to zoom into and around particular spectral regions. This is done by clicking in the Main Plot Window, either on the plot itself or its x-axis, with the left mouse button, and dragging (i.e., holding the mouse button down) to the right until you have selected the region of interest. If you overshoot, simply reselect on the new region; if you undershoot, the ``Zoom Out'' button (on the ``Button Bar'') allows you to expand the selected region slightly. In some cases, profit will ignore a request to zoom into a very small selection, since it is difficult to determine the difference between a small selection and a random click of the mouse. In this case, simply select a larger subspectrum and then zoom in further from there.

Profit can also slide spectra back and forth at a constant zoom. To do this, simply hold down the right mouse button on the Main Plot Window and simply slide the mouse left and right; the spectrum view will slide along with the mouse.

The X-axis coordinates used to display plots defaults to wavelength (Å) units, but can be easily changed to energy (keV) units temporarily by using the Energy radio button. Clicking the energy button will simply transform the spectrum displayed in the Main Plot Window into energy units, and vice versa for wavelengths. A more permanent change (which will affect future spectra loaded into profit) can be effected from the File$\rightarrow$Preferences window. To convert to velocity units, a line must be selected to use as the 0 point; see §3.3.4.